Characterization and body distribution of beta-elemene solid lipid nanoparticles (SLN).

Solid lipid nanoparticles (SLN) containing beta-elemene, a volatile oil used for the treatment of cancer, were prepared by the method combining probe sonication and membrane extrusion. Effects of the formulations and procedures on the characteristics of SLN were investigated. Body distribution of beta-elemene SLN in rats after intravenous administration was compared with that of the commercial emulsion. The results showed that dispersing the surfactant in the melted lipid matrix could obtain smaller particles than that dispersing in the water phase. Increasing the ratio of monostearin in the lipid matrix or the concentration of surfactant reduced the mean volume size of the SLN. Optimized formulation was composed of monostearin and precirol ATO 5 at a mass ratio of 3:7, which was quite stable for 8 months at room temperature. In vitro release of beta-elemene from the SLN was slow and stable without obvious burst release and was found to follow the Higuich equation. After intravenous administration, the beta-elemene levels after 5 min injection of SLN formulation were 1.5, 2.9, and 1.4 times higher than those of beta-elemene emulsion in liver, spleen, and kidney, respectively, while the concentrations of beta-elemene were decreased 30% in heart and lung. Therefore, the SLN containing beta-elemene might be an attractive candidate for the treatment of liver cancer.